This invention relates generally to pedals for use on bicycles and the like, and, more particularly, to clipless pedal/cleat assemblies of a kind including a pedal assembly that releasably secures a cleat attached to the sole of a rider's shoe.
Clipless pedal assemblies of this particular kind commonly include a main pedal body having forward and rearward cleat retainers mounted on its upper side. These cleat retainers are configured to be forcibly retractable apart from each other, against the yielding bias of a spring-bias device, or spring mechanism, to receive and releasably secure forward and rearward projections that are part of a cleat attached to the sole of a rider's shoe. The rider can release the cleat and shoe from the pedal assembly simply by rotating the shoe by a predetermined angular amount, about an axis perpendicular to the pedal body's upper side. This causes cam surfaces on the cleat to engage the forward and rearward cleat retainers and forcibly urge them apart from each other, against the yielding bias of the spring mechanism, to release the retainers' retention of the cleat.
Typically in the past, the pedal assembly's forward cleat retainer has been fixed relative to the pedal body and its rearward cleat retainer has been yieldably biased toward the forward cleat retainer by the spring mechanism. This arrangement works satisfactorily in most situations, but it is vulnerable to at least one serious problem. When the rider vigorously pushes downwardly on one pedal while pulling upwardly on the other pedal, the upward pull can sometimes overcome the bias provided by the spring mechanism and release the cleat and shoe from the pedal assembly. This, in turn, can potentially lead to serious injury of the rider. Moreover, even if the rider does not pull upwardly with sufficient force to release the cleat from the pedal assembly, any yielding by the spring mechanism absorbs and wastes energy. The severity of this problem can be reduced by increasing the force provided by the spring mechanism, but this will inherently make it more difficult to engage/disengage the cleat with/from the pedal assembly.
Another problem with typical pedal/cleat assemblies of the past has arisen because the rider's shoe typically has been secured to the pedal assembly not only by the engagement of the cleat's forward and rearward projections with the pedal assembly's forward and rearward cleat retainers, but also by the contact of lugs on the inboard and outboard sides of the shoe's sole with inboard and outboard sides of the pedal body. The involvement of portions of the rider's shoe sole in this securement can render the connection vulnerable to variations in the design and manufacturing tolerances of the shoe, which can lead to undesired vertical play or interference incompatibilities. The involvement of portions of the rider's shoe sole in this securement also can make it difficult to tailor the pedal/cleat assembly to accommodate riders having certain biomechanical issues, e.g., leg-length discrepancies and varus (knock-kneed) and valgus (bow-legged) tilt.
Yet another problem with typical pedal/cleat assemblies of the past relates to the stability of the rider's shoe on the pedal assembly, both in terms of comfort and optimal power transfer. In particular, the cleat's projections and pedal assembly's cleat retainers have needed to be precisely sized and configured, to ensure that they allow a minimum of vertical movement between them. Moreover, because of wear over time, the engagement between the cleat projections and the cleat retainers can deteriorate and allow for undesired vertical movement, or play, between the cleat and the pedal assembly.
It should, therefore, be appreciated that there is a continuing need for an improved pedal/cleat assembly that securely and stably couples the cleat to the pedal assembly without relying on portions of the rider's shoe sole, that reduces the possibility of the rider inadvertently pulling the cleat out of engagement with the pedal assembly, that allows for a convenient and precise ergonomic adjustment to accommodate riders having various biomechanical issues such as leg-length discrepancy and varus or valgus tilt, and that minimizes the possibility of undesired vertical play between the cleat and pedal assembly even after extended use and wear. The present invention fulfills these needs and provides further related advantages.